Octopus blood: a natural antifreeze?

How does an octopus survive in the below-freezing waters of the Antarctic? It seems like these animals shouldn’t be able to survive in frigid temperatures, but new research shows that they have a special protein in their blood that helps them survive.

The protein that makes octopus blood blue is called haemocyanin, and it actually works to improve the oxygen supply to the animal. When temperatures are extremely low, the animal is protected because oxygen supply to the tissues isn’t compromised. Researchers looked at the concentrations of haemocyanin in different species of octopus, and found that the Antarctic octopus, with the highest concentration of haemocyanin, was able to keep its body oxygenated better than other species.

Pretty cool – it’s kind of like these guys have their own built-in antifreeze. When researchers compare the Antarctic octopus’s adaptations to those of Antarctic fish, the differences suggest that the octopus may be better than the fish at coping with global warming.